• Experts have divided the dinosaur age into three main parts — the Triassic, Jurassic and Cretaceous periods. Different dinosaurs lived in each of these periods so some fossils are older than others.

• Many fossils of stegosaurus have been found in western North America and the famous tyrannosaurus and triceratops have been found only there, and nowhere else.

• The biggest South American meat-eater found so far is piatnitzkysaurus, which was about six metres long and three metres high. It chased and killed prey in the same way as its bigger North American relative, allosaurus.

• Besides America, some dinosaurs such as brachiosaurus have also been found in Africa, Europe, Australia and Asia. One of the biggest fossil sites in Africa is Tendaguru in Tanzania. Over 200 tonnes of dinosaur bones were found there between 1909 and 1912. Many dinosaurs were dug up, including the stegosaur kentrosaurus and the small bird-like elaphrosaurus.

• Few dinosaur fossils have been found in Australia, but thousands of fossil dinosaur footprints were uncovered in Queensland. The most complete dinosaur found there is muttaburrasaurus.

• Only one dinosaur fossil has been found in New Zealand, but the tuatara, a reptile that lives there today, looks almost exactly the same as its ancestors that lived in the dinosaur age.

• Hundreds of dinosaur remains have been found throughout Asia. The wolf-sized oviraptor was found in the remote Gobi Desert in Mongolia. Shantungosaurus, a duck-billed dinosaur — about 12 metres tall — comes from China.

• Fossils of dinosaurs have also been found in the Arctic and Antarctic. There would have been plenty of food in summer but little in winter. Experts think that dinosaurs’ herds migrated away from the poles in winter, as modern-day caribou do.

• Ostrich-sized struthiomimus was one of the fastest dinosaurs. It had no armour of horns to protect it and had to rely on speed to escape. It was as fast as a racehorse, reaching speeds of over 50 km an hour.

• The huge sauropods, like brachiosaurus were the slowest moving dinosaurs. At over 50 tonnes, they were too heavy to run and so plodded along at about 10 km an hour. Unlike smaller dinosaurs, these huge creatures were probably too big ever to have reared up in their hind legs. ·    Many scientists now agree that birds are the closest living relatives of the dinosaurs. The first fossil bird to be found was archaeopteryx. It had a reptile-like skeleton similar to that of deinonychus and featured wings like a bird. Archaeopteryx had a long bony tail, three clawed fingers on each hand and teeth. Modern birds have lost their teeth and their clawed wing fingers, their small tail stumps hold their tail feathers. —Compiled by Mohammad Bilal